H01J49/04—Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components

H01J49/0468—Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components with means for heating or cooling the sample

Abstract

The invention relates generally to sample ionization, and provides ionization probe assemblies, systems, computer program products, and methods useful for this purpose.

Description

The present application is a continuation of U.S. patent application Ser. No. 13/342,760, filed Jan. 3, 2012, which is a continuation of U.S. patent application Ser. No. 12/705,352, filed Feb. 12, 2010, now U.S. Pat. No. 8,158,936, issued Apr. 17, 2012, which claims priority to U.S. Provisional Patent Application Ser. No. 61/152,214, filed Feb. 12, 2009, the entire disclosure of which is herein incorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates generally to sample ionization, and provides ionization probe assemblies, systems, computer program products, and methods useful for this purpose.

BACKGROUND OF THE INVENTION

Mass spectrometry (MS) is an analytical technique that can be used to determine the chemical composition of a sample, and to supply data important to assigning the chemical structures of the components. It does so by ionizing the components to generate charged molecules and molecule fragments, and then measuring their mass-to-charge ratios. In an MS procedure, a sample is introduced into the MS instrument, typically by a pump or syringe, and its components undergo ionization through one of a variety of mechanisms resulting in the formation of charged particles. The mass-to-charge ratio of the particles can then be calculated based on behavior of the ions as they pass through electric and magnetic fields generated by the MS instrument.

Electrospray ionization (ESI) is one technique used in MS to produce ions. It is especially useful in producing ions from macromolecules because it overcomes the propensity of these molecules to fragment when ionized. In electrospray ionization, a liquid is pushed through a very small, charged and usually metal, capillary. This liquid contains the substance to be studied, the analyte, dissolved in a large amount of solvent, which is usually much more volatile than the analyte. Volatile acids, bases or buffers are often added to this solution too. The analyte exists as an ion in solution either in its anion or cation form. Because like charges repel, the liquid pushes itself out of the capillary and forms an aerosol. An uncharged carrier gas such as nitrogen is sometimes used to help nebulize the liquid and to help evaporate the neutral solvent in the droplets. As the solvent evaporates, the analyte molecules are forced closer together, repel each other and break up the droplets. This process is called Coulombic fission because it is driven by repulsive Coulombic forces between charged molecules. The process repeats until the analyte is free of solvent and is a lone ion.

As MS usage and applications continue to increase, there continues to be a need for improved MS systems and improved components for use in MS systems and methods.

SUMMARY OF THE INVENTION

The present invention provides ionization probe assemblies that are useful in spraying and ionizing sample materials. Typically, the ionization probe assemblies are configured to substantially continuously introduce sample materials into ion source housings of molecular mass measurement systems via multiple probes that are individually configured to discontinuously spray or otherwise introduce sample materials into the ion source housings. In some embodiments, for example, probes of the ionization probe assemblies are configured to duty cycle between spray and rinse positions that are substantially electrically isolated from one another. In addition to ionization probe assemblies, the invention also provides related molecular mass measurement systems, computer program products, and methods.

In one aspect, the invention provides an ionization probe assembly that includes at least one probe mounting structure and at least one probe that is movably coupled to the probe mounting structure. The probe is configured to discontinuously introduce sample aliquots into an ion source housing. In addition, the ionization probe assembly also includes at least one probe conveyance mechanism operably connected to the probe. The probe conveyance mechanism is configured to convey the probe between at least a first position and at least a second position. The first position is substantially electrically isolated from the second position. In some embodiments, an electrospray ion source housing includes the ionization probe assembly. In these embodiments, a mass spectrometer typically includes the electrospray ion source housing. In certain embodiments, at least one cavity is disposed in or proximal to the probe mounting structure. The cavity typically comprises the second position. In some of these embodiments, the cavity fluidly communicates with at least one outlet. Typically, the ionization probe assembly includes at least two probes that are each movably coupled to the probe mounting structure. In these embodiments, the probes are generally independently movably coupled to the probe mounting structure. In some embodiments, the ionization probe assembly comprises at least one wide-bore probe. In some embodiments, the probe mounting structure comprises a removable cartridge. In some embodiments, the removable cartridge is spring-loaded. In some embodiments, the probe mounting structure is configured to accept removable cartridges from a variety of commercial instruments. In some embodiments, the ionization probe assembly comprises one or more nebulizer gas lines configured to deliver gas from a nebulizer gas source to at least one probe. In some embodiments, one or more nebulizer gas lines comprise a thermal modulator to heat gas within one or more nebulizer gas lines.

The probe mounting structures include various embodiments. In certain embodiments, for example, the probe mounting structure includes at least one view port. In some embodiments, at least one cover operably connected to the probe mounting structure. In certain embodiments, the probe mounting structure comprises an ion source housing back plate that is configured to operably connect to an ion source housing. In these embodiments, the ion source housing back plate typically comprises at least one alignment feature that is structured to align the ion source housing back plate relative to the ion source housing when the ion source housing back plate operably connects to the ion source housing. In some embodiments, at least a first mounting component is operably connected to the probe mounting structure. The first mounting component is configured to engage at least a second mounting component that is operably connected to an ion source housing when the probe mounting structure is mounted on the ion source housing. Typically, the first and second mounting components comprise hinge and/or latch components. In certain embodiments, the probe mounting structure comprises an ion source housing. In some of these embodiments, the ion source housing comprises at least one view port.

Typically, at least one channel is disposed through a length of the probe. In addition, the probe generally comprises at least one sprayer needle that fluidly communicates with the channel. In some embodiments, at least one nebulizer gas source and/or nebulizer gas sheath fluidly communicates with the channel.

In some embodiments, the ionization probe assembly includes at least one thermal modulator operably connected to the probe. The thermal modulator is typically configured to modulate a temperature of the probe. In certain embodiments, for example, the thermal modulator comprises a nebulizer gas heater. Typically, at least one controller circuit board operably connected to the thermal modulator.

In certain embodiments, the ionization probe assembly includes at least two probes independently that are movably coupled to the probe mounting structure. Typically, each probe is movably coupled to the probe mounting structure via a pivot mechanism. In some embodiments, the probe conveyance mechanism comprises at least one motor operably connected to at least one of the pivot mechanisms via a pulley and belt drive assembly. Optionally, each probe is configured to move between a spray position and a rinse position in which the spray position is substantially electrically isolated from the rinse position. In certain embodiments, at least one cavity is disposed in or proximal to the probe mounting structure. The cavity generally comprises at least one of the rinse positions. In these embodiments, the cavity typically fluidly communicates with at least one outlet.

In some embodiments, the probe is movably coupled to the probe mounting structure via a slide mechanism. Typically, the slide mechanism comprises at least two probes. In some of these embodiments, the probes are substantially fixedly coupled to the slide mechanism. In certain embodiments, the first position comprises a spray position and the second position comprises at least first and second rinse positions that are each substantially electrically isolated from the spray position. Typically, when a first probe is in the spray position, a second probe is in the second rinse position, and when the second probe is in the spray position, the first probe is in the first rinse position. In some of these embodiments, the slide mechanism comprises a probe support plate coupled to the probe mounting structure via a linear slide, and the probe is mounted on the probe support plate. In certain embodiments, the probe conveyance mechanism comprises a dual acting pneumatic cylinder operably connected to the probe mounting structure and to the probe support plate.

In another aspect, the invention provides an ionization probe assembly that includes at least one ion source housing back plate that comprises one or more surfaces that define at least one spray orifice. The ion source housing back plate is configured to operably connect to an ion source housing. The ionization probe assembly also includes at least one rinse cavity that is at least partially disposed within the ion source housing back plate in which the rinse cavity communicates with the spray orifice via at least one opening. Typically, the rinse cavity fluidly communicates with at least one outlet. In addition, the ionization probe assembly also includes at least one probe support structure coupled to the ion source housing back plate via at least one linear slide, and at least one probe substantially fixedly mounted on the probe support structure. The ionization probe assembly also includes at least one probe conveyance mechanism operably connected to the probe support structure. The probe conveyance mechanism is configured to selectively convey the probe support structure such that the probe slides between the spray orifice and the rinse cavity through the opening.

In another aspect, the invention provides an ionization probe assembly that includes at least one ion source housing back plate that comprises one or more surfaces that define at least one spray orifice. The ion source housing back plate is configured to operably connect to an ion source housing. The ionization probe assembly also includes at least one rinse cavity that is at least partially disposed within the ion source housing back plate in which the rinse cavity communicates with the spray orifice via at least one opening, and at least one probe movably coupled to the ion source housing back plate via at least one pivot mechanism. In addition, the ionization probe assembly also includes at least one probe conveyance mechanism that comprises at least one motor operably connected to the pivot mechanism via a pulley and belt drive assembly. The probe conveyance mechanism is configured to selectively convey the probe between the spray orifice and the rinse cavity through the opening.

In another aspect, the invention provides a molecular mass measurement system. The system includes at least one mass spectrometer that comprises at least one ion source housing, and at least one ionization probe assembly operably connected to the ion source housing. The ionization probe assembly comprises: at least one probe mounting structure; at least one probe that comprises at least one inlet and at least one outlet in which the inlet fluidly communicates with the outlet, the probe is movably coupled to the probe mounting structure, which probe is configured to discontinuously introduce sample aliquots into the ion source housing; and at least one probe conveyance mechanism operably connected to the probe, which probe conveyance mechanism is configured to convey the probe between a spray position and a rinse position in which the spray position is substantially electrically isolated from the rinse position. The system also includes at least one sample source in fluid communication with the inlet of the probe, and at least one rinse fluid source in fluid communication with the inlet of the probe. In addition, the system also includes at least one controller operably connected at least to the ionization probe assembly. The controller is configured to selectively direct the ionization probe assembly to: (a) convey the probe from the rinse position to the spray position; (b) spray at least one sample aliquot into the ion source housing from the sample source when the probe is in the spray position; (c) convey the probe from the spray position to the rinse position; and (d) rinse the probe with rinse fluid from the rinse fluid source when the probe is in the rinse position. In some embodiments, the system includes at least one additional system component selected from, e.g., at least one nucleic acid amplification component; at least one sample preparation component; at least one microplate handling component; at least one mixing station; at least one material transfer component; at least one sample processing component; at least one database; and the like.

In another aspect, the invention provides a computer program product that includes a computer readable medium having one or more logic instructions for directing an ionization probe assembly of a molecular mass measurement system to: (a) convey a first probe from a first rinse position to a first spray position of the molecular mass measurement system, wherein the first rinse position and the first spray position are substantially electrically isolated from one another; (b) convey a second probe from a second spray position to a second rinse position of the molecular mass measurement system, wherein the second spray position and the second rinse position are substantially electrically isolated from one another; (c) spray at least a first sample aliquot into an ion source housing of the molecular mass measurement system via the first probe when the first probe is in the first spray position; (d) rinse the second probe when the second probe is in the second rinse position; (e) convey the first probe from the first spray position to the first rinse position; (f) convey the second probe from the second rinse position to the second spray position; (g) spray at least a second sample aliquot into the ion source housing of the molecular mass measurement system via the second probe when the second probe is in the second spray position; and, (h) rinse the first probe when the first probe is in the first rinse position. In some embodiments, the computer program product includes at least one logic instruction for directing the ionization probe assembly of the molecular mass measurement system to modulate a temperature of the first probe and/or second probe using at least one thermal modulator operably connected to the first probe and/or second probe. In certain embodiments, the logic instructions are configured to direct the ionization probe assembly to execute (a) substantially simultaneously with (b), (c) substantially simultaneously with (d), (e) substantially simultaneously with (f), and/or (g) substantially simultaneously with (h). Typically, a controller of the molecular mass measurement system comprises the logic instructions.

In another aspect, the invention provides a method of spraying sample aliquots into an ion source housing of a molecular mass measurement system. The method includes (a) conveying a first probe from a first rinse position to a first spray position of the molecular mass measurement system in which the first rinse position and the first spray position are substantially electrically isolated from one another and wherein the first spray position is in fluid communication with the ion source housing; and (b) conveying a second probe from a second spray position to a second rinse position of the molecular mass measurement system, wherein the second spray position and the second rinse position are substantially electrically isolated from one another. The method also includes (c) spraying at least a first sample aliquot into the ion source housing via the first probe when the first probe is in the first spray position; (d) rinsing the second probe when the second probe is in the second rinse position; and (e) conveying the first probe from the first spray position to the first rinse position. In addition, the method also includes (f) conveying the second probe from the second rinse position to the second spray position in which the second spray position is in fluid communication with the ion source housing; (g) spraying at least a second sample aliquot into the ion source housing of the molecular mass measurement system via the second probe when the second probe is in the second spray position; and (h) rinsing the first probe when the first probe is in the first rinse position, thereby spraying the sample aliquots into the ion source housing of the molecular mass measurement system. In certain embodiments, the method includes performing (a) substantially simultaneously with (b), (c) substantially simultaneously with (d), (e) substantially simultaneously with (f), and/or (g) substantially simultaneously with (h).

In some embodiments, the method includes modulating a temperature of the first probe and/or second probe using at least one thermal modulator operably connected to the first probe and/or second probe. Typically, the method includes ionizing the first sample aliquot and the second sample aliquot when the first sample aliquot and the second sample aliquot are sprayed into the ion source housing. The method also generally includes measuring a molecular mass of at least one component of the first sample aliquot and/or the second sample aliquot using the molecular mass measurement system. In some embodiments, the component of the first sample aliquot and/or the second sample aliquot comprises at least one nucleic acid molecule. In these embodiments, the method generally comprises determining a base composition of the nucleic acid molecule from the molecular mass of the nucleic acid molecule. In certain of these embodiments, the method includes correlating the base composition of the nucleic acid molecule with an identity or property of the nucleic acid molecule.

BRIEF DESCRIPTION OF THE DRAWINGS

The description provided herein is better understood when read in conjunction with the accompanying drawings which are included by way of example and not by way of limitation. It will be understood that like reference numerals identify like components throughout the drawings, unless the context indicates otherwise. It will also be understood that some or all of the figures may be schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown.

FIG. 1 schematically shows an exemplary dual sprayer mounted on a time of flight spectrometer (TOF).

FIG. 15 schematically shows a rear-view of an exemplary wide-bore dual sprayer with two probes mounted on an ion source housing.

FIG. 16 schematically shows a side-view of an exemplary wide-bore dual sprayer with two probes mounted on an ion source housing.

FIG. 17 schematically shows a front-view of an exemplary wide-bore dual sprayer with two probes mounted on an ion source housing.

FIG. 18 schematically shows a top-view of an exemplary wide-bore dual sprayer with two probes mounted on an ion source housing.

DETAILED DESCRIPTIONI. Definitions

Before describing the invention in detail, it is to be understood that this invention is not limited to particular cartridges, mixing stations, systems, kits, or methods, which can vary. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” also include plural referents unless the context clearly provides otherwise. Thus, for example, reference to “a cartridge” includes a combination of two or more cartridge. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. Further, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In describing and claiming the invention, the following terminology, and grammatical variants thereof, will be used in accordance with the definitions set forth below.

The term “communicate” refers to the direct or indirect transfer or transmission, and/or capability of directly or indirectly transferring or transmitting, something at least from one thing to another thing. Objects “fluidly communicate” with one another when fluidic material is, or is capable of being, transferred from one object to another.

The term “material” refers to something comprising or consisting of matter. The term “fluidic material” refers to material (such as, a liquid or a gas) that tends to flow or conform to the outline of its container.

The term “molecular mass” refers to the mass of a compound as determined using mass spectrometry, for example, ESI-MS. Herein, the compound is preferably a nucleic acid. In some embodiments, the nucleic acid is a double stranded nucleic acid (e.g., a double stranded DNA nucleic acid). In some embodiments, the nucleic acid is an amplicon. When the nucleic acid is double stranded the molecular mass is determined for both strands. In one embodiment, the strands may be separated before introduction into the mass spectrometer, or the strands may be separated by the mass spectrometer (for example, electro-spray ionization will separate the hybridized strands). The molecular mass of each strand is measured by the mass spectrometer.

The term “system” refers a group of objects and/or devices that form a network for performing a desired objective.

II. Introduction

The invention relates to ionization probe assemblies that are useful in spraying and ionizing sample materials, and in various embodiments provides individual sub-components, software, control components, and related methods employing the assemblies. In some embodiments, the ionization probe assemblies are configured to substantially continuously introduce sample materials into ion source housings of molecular mass measurement systems via multiple probes that are individually configured to discontinuously spray or otherwise introduce sample materials into the ion source housings. In some embodiments, for example, probes of the ionization probe assemblies are configured to duty cycle between spray and rinse positions that are substantially electrically isolated from one another.

III. Example Systems

A. Dual Sprayer

FIG. 1 shows a representative time of flight spectrometer (TOF) 100 having an exemplary dual sprayer 110 mounted thereon. FIG. 2 shows the dual sprayer 110 mounted on a TOF chamber 101, showing the chamber detached from the TOF. FIG. 3 shows the dual sprayer 110 separate from the TOF or the TOF chamber. The dual sprayer 110 comprises an ionization probe assembly that includes at least one probe mounting structure 120 and two probes 130 that are movably coupled to the probe mounting structure 120. Any number of configurations may be used to movably couple the probes 130 to the probe mounting structure 120, so long as the desired position and movement of the probes 130 is provided. The probes 130 are configured to discontinuously introduce sample aliquots into the TOF chamber 101 (not shown in FIG. 3). Samples are introduced into a probe via a probe opening 140. The probe 130 may be mounted on a probe conveyance mechanism 150, operably connected to the probe. The probe conveyance mechanism 150 is configured to convey the probe between at least a first position and at least a second position. As shown in FIG. 3, the two probes 130 are configured to pivot around an axis 160 permitting movement from the first position to the second position. The first position is substantially electrically isolated from the second position. The dual sprayer 110 may comprise least two independent probes 130 that are movably coupled to the probe mounting structure 120. Each probe is movably coupled to the probe mounting structure 120 via a pivot mechanism 125. The probe conveyance mechanism 150 comprises a motor 151 operably connected to a pivot mechanisms 125 via belt drive 152.

FIGS. 4a and 4b show a side view of the dual sprayer 110. In FIG. 4a, the front-most probe 130 is shown in the second position, or “spray” position. In FIG. 4b the front-most probe 130 is shown in the first position, or “rinse” position. A cavity is disposed in or proximal to the probe mounting structure 120 to permit movement of the probe 130 into the second position. The cavity typically comprises the second position. In some of these embodiments, the cavity fluidly communicates with at least one outlet. The probes 130 are generally independently movably coupled to the probe mounting structure 120. In certain embodiments, the probe mounting structure 120 includes at least one view port 123 (FIG. 8) to permit viewing of the probes. The one or more view ports 123 (FIG. 8) may comprise a glass, plastic, ceramic or other transparent material to provide a window located on any desired region of the mounting structure 120.

FIG. 5 shows a dual sprayer 110 comprising a cover 200 affixed to and covering the mounting structure 120. The cover 200 may be made of any desired material and can substantially or partially cover the mounting structure 120. The cover 200 may be affixed to the mounting structures by screws, bolts, clamps, pins, or via any other connection means. The cover may comprise one or more slots or openings 210 to allow the probe(s) 130 to stick through the cover 200 and permit the probe(s) 130 to move uninhibited by the cover 200. The cover 200 may further comprise one or more slots or openings that serve as vents 220 to permit air to circulate in and out of the cover 200. One or more fans or pumps (not shown) may also be employed to assist in circulation of air or other gasses throughout the system.

As shown in FIGS. 6a and 6b, the probe mounting structure 120 may comprise an ion source housing back plate 230 that is configured to operably connect to an ion source housing 300. FIGS. 6a and 6b show alternative ion source housing back plates 230 configured for attachment to two different ion source housing 300 configurations. The ion source housing back plate 230 typically comprises at least one alignment feature (not shown) that is structured to align the ion source housing back plate 230 relative to the ion source housing 300 when the ion source housing back plate 230 operably connects to the ion source housing 300. Examples of alignment features include, but are not limited to, markings, grooves, alignment holes, alignment pegs, and the like.

As shown in FIG. 7, the probe 130 comprises at least one channel 131 disposed through a length of the probe 130. The probe 130 may comprise at least one sprayer needle 132 that fluidly communicates with the channel 131. A nebulizer gas source and/or nebulizer gas sheath 133 fluidly communicates with the channel. The probe 130 may also comprise a thermal modulator, configured to modulate a temperature of the probe 130, comprising a nebulizer gas heater 134 and a controller circuit board 135.

As shown in FIG. 8, a first mounting 121 component is operably connected to the probe mounting structure 120. The first mounting component is configured to engage at least a second mounting component (not shown) that is operably connected to an ion source housing 300 (not shown in FIG. 8) when the probe mounting structure 120 is mounted on the ion source housing 300 (not shown in FIG. 8). The first 121 and second (not shown) mounting components may comprise hinge and/or latch components or any other means to moveably attached the mounting structure 120 to the ion source housing 300.

The probe may be movably coupled to the probe mounting structure 120 via a slide mechanism 400. The slide mechanism 400 comprises at least two probes 130, substantially fixedly coupled to the slide mechanism 400, and capable of sliding between a first position and a second position. The first position 130a comprises a spray position and the second position comprises at least first 130b and second 130c rinse positions that are each substantially electrically isolated from the spray position. When a first probe 130 is in the spray position 130a, a second probe 130 is in the second rinse position 130b, and when the second probe 130 is in the spray position 130a, the first probe is in the first rinse position 130c. The slide mechanism 400 comprises a probe support plate 420 coupled to the probe mounting structure 120 via a linear slide 410, and the probe is mounted on the probe support plate 420. The probe slide mechanism comprises a dual acting pneumatic cylinder 430 operably connected to the probe mounting structure 120 and to the probe support plate 420.

As shown in FIG. 8, an ion source housing back plate 230 comprises one or more surfaces that define at least one spray orifice 139. The dual sprayer assembly 110 also includes at least one rinse cavity 136 that is at least partially disposed within the ion source housing back plate 230 in which the rinse cavity 136 fluidly communicates with at least one outlet 138. The dual sprayer assembly 110 also includes at least one probe support structure 120 coupled to the ion source housing back plate 230 via at least one linear slide 410, and at least one probe 130 substantially fixedly mounted on the probe support structure 120. The probe conveyance mechanism 150 is operably connected to the probe support structure 120. The probe conveyance mechanism 150 is configured to selectively convey the probe support structure 120, such that the probe 130 slides between the spray orifice 139 and the rinse cavity 136 through the opening.

In some embodiments, the invention provides a molecular mass measurement system. The system includes time of flight spectrometer (TOF) 100 that comprises at least one ion source housing 300, and at least one dual sprayer assembly 110 operably connected to the ion source housing 300. The dual sprayer assembly 110 comprises: at least one probe mounting structure 120; at least one probe 130 that comprises a probe opening 140 that can serve as a fluid inlet and a sprayer needle 132 that can serve as a fluid outlet in which the probe opening 140 communicates with the sprayer needle 132 via a channel 131. The probe 130 is movably coupled to the probe mounting structure 120, which probe is configured to discontinuously introduce sample aliquots into the ion source housing 300; and at least one probe conveyance mechanism 150 operably connected to the probe 130, which probe conveyance mechanism 150 is configured to convey the probe 130 between a spray position 130a and a rinse position 130b in which the spray position 130a is substantially electrically isolated from the rinse position 130b.

B. Wide-Bore Dual Sprayer

FIG. 10 shows a representative time of flight spectrometer (TOF) 100 having an exemplary wide-bore dual sprayer 510 mounted thereon. FIG. 11 shows the wide-bore dual sprayer 510 and wide-bore cover 600 mounted on a TOF chamber 101, showing the chamber detached from the TOF 100. FIG. 12 shows the wide-bore dual sprayer 510 separate from the TOF 100 or the TOF chamber 101. The wide-bore dual sprayer 510 comprises an ionization probe assembly that includes at least one wide-bore probe mounting structure 520 and one wide-bore probe 530 (e.g. 1 probe, 2 probes, 3 probes, 4 probes, 5, probes, 10 probes, etc.) that are movably coupled to the wide-bore probe mounting structure 520. Any number of configurations may be used to movably couple the wide-bore probes 530 to the wide-bore probe mounting structure 520, so long as the desired position and movement of the wide-bore probes 530 is provided. The wide-bore probes 530 are configured to discontinuously introduce sample aliquots into the TOF chamber 101 (not shown in FIG. 12). Samples are introduced into a wide-bore probe 530 via a wide-bore probe opening 540. The wide-bore probe 530 may be mounted on a probe conveyance mechanism 150, operably connected to the probe. In some embodiments, the probe conveyance mechanism 150 for the wide-bore dual sprayer 510 is identical or substantially similar to the probe conveyance mechanism 150 of a non-wide-bore dual sprayer 110 (e.g. narrow gauge dual sprayer). In some embodiments, the probe conveyance mechanism 150 for the wide-bore dual sprayer 510 is specifically designed for use with the wide-bore dual sprayer 510. The probe conveyance mechanism 150 is configured to convey the probe between at least a first position and at least a second position. As shown in FIG. 12, the two probes 130 are configured to pivot around an axis 160 permitting movement from the first position to the second position. In some embodiments, the first position is substantially electrically isolated from the second position. In some embodiments, the wide-bore dual sprayer 510 may comprise least two independent wide-bore probes 530 that are movably coupled to the probe mounting structure 120. Each probe is movably coupled to the probe mounting structure 120 via a wide-bore pivot mechanism 525. The probe conveyance mechanism 150 comprises a motor 151 operably connected to a wide-bore pivot mechanisms 525 via belt drive 152.

FIGS. 13a and 13b show a side view of the wide-bore dual sprayer 510. In FIG. 13a, the front-most wide-bore probe 530 is shown in the second position, or “spray” position. In FIG. 13b the front-most wide-bore probe 530 is shown in the first position, or “rinse” position. In some embodiments, a cavity is disposed in or proximal to the wide-bore probe mounting structure 520 to permit movement of the wide-bore probe 530 into the second position. The cavity typically comprises the second position. In some of these embodiments, the cavity fluidly communicates with at least one outlet. The wide-bore probes 530 are generally independently movably coupled to the wide-bore probe mounting structure 520. In certain embodiments, the wide-bore probe mounting structure 120 includes at least one view port 123 (FIG. 8) to permit viewing of the wide-bore probes 530. The one or more view ports 123 (FIG. 8) may comprise a glass, plastic, ceramic or other transparent material to provide a window located on any desired region of the wide-bore mounting structure 520. In some embodiments, a wide-bore mounting structure 520 comprises a outlet and/or drain of sufficient size to prevent kick-back.

FIG. 14 shows a wide-bore dual sprayer 510 comprising a wide-bore cover 600 affixed to and covering the wide-bore mounting structure 520. In some embodiments, the wide-bore cover 600 is made of any desired material and can substantially or partially cover the wide-bore mounting structure 520. In some embodiments, the wide-bore cover 600 is affixed to the mounting structures by screws, bolts, clamps, pins, or via any other connection means. In some embodiments, the wide-bore cover 600 comprises one or more slots or openings 210 to allow the wide-bore probe(s) 530 to stick through the wide-bore cover 600 and permit the wide-bore probe(s) 530 to move uninhibited past the wide-bore cover 600. In some embodiments, the wide-bore cover 600 further comprises one or more slots or openings that serve as vents 220 to permit air to circulate in and out of the wide-bore cover 600. In some embodiments, one or more fans or pumps are employed to assist in circulation of air or other gasses throughout the system.

In some embodiments, the wide-bore probe mounting structure 520 comprises an ion source housing back plate 230 that is configured to operably connect to an ion source housing 300. FIGS. 6a, 6b, and 12 show alternative ion source housing back plates 230 configured for attachment to different ion source housing 300 configurations. In some embodiments, a wide-bore dual sprayer utilizes an identical or substantially similar ion source housing back plate 230 and/or ion source housing 300 to the non-wide-bore dual sprayer 110 (e.g. narrow gauge dual sprayer). In some embodiments, the ion source housing back plate 230 and/or ion source housing 300 specifically designed for use with the wide-bore dual sprayer 510. The ion source housing back plate 230 typically comprises at least one alignment feature that is structured to align the ion source housing back plate 230 relative to the ion source housing 300 when the ion source housing back plate 230 operably connects to the ion source housing 300. Examples of alignment features include, but are not limited to, markings, grooves, alignment holes, alignment pegs, and the like.

The wide-bore probe 530 may be movably coupled to the probe mounting structure 520 via a slide mechanism 400. The slide mechanism 400 comprises at least two wide-bore probes 530, substantially fixedly coupled to the slide mechanism 400, and capable of sliding between a first position 130a and a second position 130b (SEE FIG. 8). In some embodiments, wide-bore probes 530 of a wide-bore dual sprayer 510 are configured to move between spray and rinse positions in substantially similar (e.g. similar, identical, etc.) fashion to non-wide-bore, standard, and/or narrow gauge probes 130. In some embodiments, a wide-bore dual sprayer 510 comprises many or all of the same or similar components as a non-wide-bore, standard, and/or narrow gauge dual sprayer 110 (e.g. spray orifice 139, rinse cavity 136, outlet 138, one linear slide 410, probe conveyance mechanism 150, time of flight spectrometer (TOF) 100, etc.).

In some embodiments, the present invention provides an ion source for generating ions for mass spectrometric analysis. In some embodiments, an ion source comprises electrospray ionization, photoionization, matrix-assisted laser desorption/ionization, chemical ionization, etc. In some embodiments, the present invention provides electrospray ionization. In some embodiments, ionization comprises forcing a liquid through a very small, charged (e.g. usually metal) capillary (Fenn et al. (1990) Mass Spectrometry Reviews 9 (1): 37-70, herein incorporated by reference in its entirety). In some embodiments, a nebulizer is utilized provide an uncharged carrier gas (e.g. nitrogen, argon, etc.) to help nebulize the liquid and to help evaporate the neutral solvent in the droplets. In some embodiments, as the solvent evaporates, the analyte molecules are forced closer together, repel each other and break up the droplets. In some embodiments, the process repeats until the analyte is free of solvent and is a bare ion. In some embodiments, the present invention provides a nebulizer, nebulizer system, and/or nebulizer apparatus to aid in the ionization process. In some embodiments, a nebulizer and/or nebulizer system comprises a nebulizer gas source, nebulizer gas lines 570, nebulizer gas-source connector 560, nebulizer gas connector 580, wide-bore nebulizer gas sheath 533 (and/or nebulizer gas sheath 133), and wide-bore nebulizer gas heater 534 (and/or nebulizer gas heater 134). In some embodiments a nebulizer and/or nebulizer system further comprises a capillary, spray nozzle, insulation element, etc. In some embodiments, an insulation element, wide-bore nebulizer gas heater 534, and/or nebulizer gas heater 134 is configured to provide gas to a nebulizer at an appropriate temperature. In some embodiments, nebulizer gas is heated using ambient heat, heat from the mass spectrometer unit, and/or heat from a wide-bore nebulizer gas heater 534, and/or nebulizer gas heater 134. In some embodiments, nebulizer gas lines 570 are lined or coated with one or more heating elements. In some embodiments, heating elements lining or coating the nebulizer gas lines 570 may take any suitable form (e.g. resistance coils, thermal tape, adhesive heater, etc.). In some embodiments, a nebulizer gas heater provides a suitable level of heating to the nebulizer gas lines or other portion of the nebulizer system (e.g. 10% heating . . . 25% heating . . . 50% heating . . . 75% heating . . . 90% heating, etc.). In some embodiments, operation and heat level of a nebulizer gas heater are maintained using one or more sensors (e.g. temperature sensor, function sensor, resistance sensor, etc.).

In some embodiments, a wide-bore probe mounting structure 520 (and/or probe mounting structure 120) is provided as a removable cartridge. In some embodiments, a wide-bore probe mounting structure 520 (and/or probe mounting structure 120) is removable as a single unit. In some embodiments, a wide-bore probe mounting structure 520 (and/or probe mounting structure 120) is removable in one or more pieces (e.g. 1, 2, 3, 4, 5, 6, etc.). In some embodiments, the removable cartridge is spring-loaded to provide ease of removal. In some embodiments, the removable cartridge is replaceable. In some embodiments, the present invention is configured to accept a number of different cartridge configurations (e.g. application specific cartridge configurations).

C. Operation

In some embodiments, the present invention provides a controller configured to selectively direct the ionization probe assembly 110 (or wide-bore probe assembly 510) to: (a) convey the probe from the rinse position 130b to the spray position 130a; (b) spray at least one sample aliquot into the ion source housing 300 from the sample source when the probe is in the spray position 130a; (c) convey the probe from the spray position 130a to the rinse position 130b; and (d) rinse the probe with rinse fluid from a rinse fluid source when the probe is in the rinse position 130b. In some embodiments, a rinse fluid source is contained on or within the TOF spectrometer 100, TOF chamber 101, or the dual sprayer assembly 110 (or wide-bore dual sprayer assembly 510) or is located externally to the sprayer and spectrometer devices.

In some embodiments, the system includes at least one additional system component selected from, e.g., at least one nucleic acid amplification component; at least one sample preparation component; at least one microplate handling component; at least one mixing station; at least one material transfer component; at least one sample processing component; at least one database; and the like.

In some embodiments, the invention provides a computer program product that includes a computer readable medium having one or more logic instructions for directing an ionization probe assembly of a molecular mass measurement system as shown in FIGS. 9a and b: (a) convey a first probe 130 (or first wide-bore probe 530) from a first rinse position 130b to a first spray position 130a of the molecular mass measurement system, wherein the first rinse position 130b and the first spray position 130a are substantially electrically isolated from one another; (b) convey a second probe from a second spray position 130c to a second rinse position 130d of the molecular mass measurement system, wherein the second spray position 130c and the second rinse position 130d are substantially electrically isolated from one another; (c) spray at least a first sample aliquot into an ion source housing 300 of the molecular mass measurement system via the first probe 130 (or first wide-bore probe 530) when the first probe is in the first spray position 130a; (d) rinse the second probe 130 (or second wide-bore probe 530) when the second probe is in the second rinse position 130d; (e) convey the first probe from the first spray position 130a to the first rinse position 130b; (f) convey the second probe from the second rinse position 130d to the second spray position 130c; (g) spray at least a second sample aliquot into the ion source housing of the molecular mass measurement system via the second probe 130 (or second wide-bore probe 530) when the second probe 130 (or second wide-bore probe 530) is in the second spray position 130c; and, (h) rinse the first probe 130 (or first wide-bore probe 530) when the first probe 130 (or first wide-bore probe 530) is in the first rinse position 130b. In some embodiments, the computer program product includes at least one logic instruction for directing the dual spray assembly 110 of the molecular mass measurement system to modulate a temperature of the first probe 130 (or first wide-bore probe 530) and/or second probe 130 (or second wide-bore probe 530) using at least one thermal modulator operably connected to the first probe and/or second probe. In certain embodiments, the logic instructions are configured to direct the dual spray assembly 110 to execute (a) substantially simultaneously with (b), (c) substantially simultaneously with (d), (e) substantially simultaneously with (f), and/or (g) substantially simultaneously with (h). Typically, a controller of the molecular mass measurement system comprises the logic instructions.

In another aspect, the invention provides a method of spraying sample aliquots into an ion source housing of a molecular mass measurement system. The method includes (a) conveying a first probe 130 (or first wide-bore probe 530) from a first rinse position 130b to a first spray position 130a of the molecular mass measurement system in which the first rinse position 130b and the first spray position 130a are substantially electrically isolated from one another and wherein the first spray position 130a is in fluid communication with the ion source housing 300; and (b) conveying a second probe 130 (or second wide-bore probe 530) from a second spray position 130c to a second rinse position 130d of the molecular mass measurement system, wherein the second spray position 130c and the second rinse position 130d are substantially electrically isolated from one another. The method also includes (c) spraying at least a first sample aliquot into the ion source housing 300 via the first probe 130 (or first wide-bore probe 530) when the first probe 130 (or first wide-bore probe 530) is in the first spray position 130a; (d) rinsing the second probe 130 (or second wide-bore probe 530) when the second probe 130 (or second wide-bore probe 530) is in the second rinse position 130d; and (e) conveying the first probe 130 from the first spray position 130a to the first rinse position 130b. In addition, the method also includes (f) conveying the second probe 130 (or wide-bore probe 530) from the second rinse position 130d to the second spray position 130c in which the second spray position 130c is in fluid communication with the ion source housing 300; (g) spraying at least a second sample aliquot into the ion source housing 300 of the molecular mass measurement system via the second probe 130 (or second wide-bore probe 530) when the second probe 130 (or second wide-bore probe 530) is in the second spray position 130c; and (h) rinsing the first probe 130 (or first wide-bore probe 530) when the first probe is in the first rinse position 130b, thereby spraying the sample aliquots into the ion source housing 300 of the molecular mass measurement system. In certain embodiments, the method includes performing (a) substantially simultaneously with (b), (c) substantially simultaneously with (d), (e) substantially simultaneously with (f), and/or (g) substantially simultaneously with (h).

In some embodiments, the method includes modulating a temperature of the first probe and/or second probe using at least one thermal modulator operably connected to the first probe 130 (or first wide-bore probe 530) and/or second probe 130 (or second wide-bore probe 530). Typically, the method includes ionizing the first sample aliquot and the second sample aliquot when the first sample aliquot and the second sample aliquot are sprayed into the ion source housing 300. The method also generally includes measuring a molecular mass of at least one component of the first sample aliquot and/or the second sample aliquot using the molecular mass measurement system.

In some embodiments, the component of the first sample aliquot and/or the second sample aliquot comprises at least one nucleic acid molecule. In these embodiments, the method generally comprises determining a base composition of the nucleic acid molecule from the molecular mass of the nucleic acid molecule. In certain of these embodiments, the method includes correlating the base composition of the nucleic acid molecule with an identity or property of the nucleic acid molecule.

In some embodiments, one or more controllers and/or computers may be operably attached to devices of the present invention to select conditions under which molecular mass measurement are made using a device of the present invention. The controllers and/or computers configured to operate with devices described herein are generally configured to effect, e.g., temperature, sample volume, number of runs, sample switching, probe rinsing conditions, spray conditions, etc. Controllers and/or computers are typically operably connected to one or more system components, such as motors (e.g., via motor drives), thermal modulating components, detectors, motion sensors, fluidic handling components, robotic translocation devices, or the like, to control operation of these components. Controllers and/or other system components is/are generally coupled to an appropriately programmed processor, computer, digital device, or other logic device or information appliance (e.g., including an analog to digital or digital to analog converter as needed), which functions to instruct the operation of these instruments in accordance with preprogrammed or user input instructions (e.g., mixing mode selection, fluid volumes to be conveyed, etc.), receive data and information from these instruments, and interpret, manipulate and report this information to the user.

A controller or computer optionally includes a monitor which is often a cathode ray tube (“CRT”) display, a flat panel display (e.g., active matrix liquid crystal display, liquid crystal display, etc.), or others. Computer circuitry is often placed in a box, which includes numerous integrated circuit chips, such as a microprocessor, memory, interface circuits, and others. The box also optionally includes a hard disk drive, a floppy disk drive, a high capacity removable drive such as a writeable CD-ROM, and other common peripheral elements. Inputting devices such as a keyboard or mouse optionally provide for input from a user.

In some embodiments, a computer includes appropriate software for receiving user instructions, either in the form of user input into a set of parameter fields, e.g., in the form of preprogrammed instructions, e.g., preprogrammed for a variety of different specific operations. The software then converts these instructions to appropriate language for instructing the operation of one or more controllers to carry out the desired operation, e.g., rinsing probe, switching fluids, taking mass measurements, or the like. The computer then receives the data from, e.g., sensors/detectors included within the system, and interprets the data, either provides it in a user understood format, or uses that data to initiate further controller instructions, in accordance with the programming.

More specifically, the software utilized to control the operation of the devices and systems of the invention typically includes logic instructions that selectively direct, e.g., motors to more probes, rate of probe movement, rate of sampling, data acquisition, and the like. The logic instructions of the software are typically embodied on a computer readable medium, such as a CD-ROM, a floppy disk, a tape, a flash memory device or component, a system memory device or component, a hard drive, a data signal embodied in a carrier wave, and/or the like. Other computer readable media are known to persons of skill in the art. In some embodiments, the logic instructions are embodied in read-only memory (ROM) in a computer chip present in one or more system components, without the use of personal computers.

The computer can be, e.g., a PC (Intel x86 or Pentium chip-compatible DOS™, OS2™, WINDOWS™, WINDOWS NT™, WINDOWS98™, WINDOWS2000™, WINDOWS XP™, WINDOWS Vista™, LINUX-based machine, a MACINTOSH™, Power PC, or a UNIX-based (e.g., SUN™ work station) machine) or other common commercially available computer which is known to one of skill. Standard desktop applications such as word processing software (e.g., Microsoft Word™ or Corel WordPerfect™) and database software (e.g., spreadsheet software such as Microsoft Excel™, Corel Quattro Pro™, or database programs such as Microsoft Access™ or Paradox™) can be adapted to the present invention. Software for performing, e.g., sample processing unit container rotation, material conveyance to and/or from sample processing unit containers, mixing process monitoring, assay detection, and data deconvolution is optionally constructed by one of skill using a standard programming language such as Visual basic, C, C++, Fortran, Basic, Java, or the like.

Devices and systems of the invention may also include at least one robotic translocation or gripping component that is structured to grip and translocate fluids, containers, or other components between components of the devices or systems and/or between the devices or systems and other locations (e.g., other work stations, etc.). A variety of available robotic elements (robotic arms, movable platforms, etc.) can be used or modified for use with these systems, which robotic elements are typically operably connected to controllers that control their movement and other functions.

In some embodiments, a wide-bore dual sprayer 510 is operationally similar to a non-wide-bore, standard, and/or narrow-gauge dual sprayer 110. In some embodiments, dual sprayers 110 a wide-bore dual sprayers 510 are configured to accommodate cartridge assemblies of commercial instruments. In some embodiments, dual sprayers 110 a wide-bore dual sprayers 510 comprise a spring-loaded portion (e.g. comprising wide-bore probes, wide-bore pivot mechanism 525, and related structures). In some embodiments, one or more portions, elements, and/or components are configured to be readily removable from the dual sprayer 110 a wide-bore dual sprayer 510 (e.g. for easy replacement). In some embodiments, a wide-bore dual sprayer 510 comprises a drain hole which is larger than that of a non-wide-bore, standard, and/or narrow-gauge dual sprayer 110 (e.g. larger drain hole prevent gas from kicking back up).

While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be clear to one skilled in the art from a reading of this disclosure that various changes in form and detail can be made without departing from the true scope of the invention. For example, all the techniques and apparatus described above can be used in various combinations. All publications, patents, patent applications, and/or other documents cited in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent, patent application, and/or other document were individually indicated to be incorporated by reference for all purposes.

Claims (9)

What is claimed is:

1. An ionization probe assembly, comprising:

at least one ion source housing back plate that comprises one or more surfaces that define at least one spray orifice, which ion source housing back plate is configured to operably connect to an ion source housing;

at least one probe support structure coupled to the ion source housing back plate via at least one linear slide;

at least one probe substantially fixedly mounted on the probe support structure; and,

at least one probe conveyance mechanism operably connected to the probe support structure, which probe conveyance mechanism is configured to convey the probe between at least a first position and a second position, wherein the first position is substantially electrically isolated from the second position.

2. An ionization probe assembly, comprising:

at least one ion source housing back plate that comprises one or more surfaces that define at least one spray orifice, which ion source housing back plate is configured to operably connect to an ion source housing;

at least one probe movably coupled to the ion source housing back plate via at least one pivot mechanism; and,

at least one probe conveyance mechanism that comprises at least one motor operably connected to the pivot mechanism via a pulley and belt drive assembly, which probe conveyance mechanism is configured to selectively convey the probe between at least a first position and a second position, wherein the first position is substantially electrically isolated from the second position.

3. A method of spraying sample aliquots into an ion source housing of a molecular mass measurement system, the method comprising:

(a) conveying a first probe from a first rinse position to a first spray position of the molecular mass measurement system, wherein the first rinse position and the first spray position are substantially electrically isolated from one another and wherein the first spray position is in fluid communication with the ion source housing;

(b) conveying a second probe from a second spray position to a second rinse position of the molecular mass measurement system, wherein the second spray position and the second rinse position are substantially electrically isolated from one another;

(c) spraying at least a first sample aliquot into the ion source housing via the first probe when the first probe is in the first spray position;

(d) rinsing the second probe when the second probe is in the second rinse position;

(e) conveying the first probe from the first spray position to the first rinse position;

(f) conveying the second probe from the second rinse position to the second spray position, wherein the second spray position is in fluid communication with the ion source housing;

(g) spraying at least a second sample aliquot into the ion source housing of the molecular mass measurement system via the second probe when the second probe is in the second spray position.

5. The method of claim 3, comprising modulating a temperature of the first probe and/or second probe using at least one thermal modulator operably connected to the first probe and/or second probe.

6. The method of claim 4, comprising ionizing the first sample aliquot and the second sample aliquot when the first sample aliquot and the second sample aliquot are sprayed into the ion source housing.

7. The method of claim 4, comprising measuring a molecular mass of at least one component of the first sample aliquot and/or the second sample aliquot using the molecular mass measurement system.

8. The method of claim 4, wherein the component of the first sample aliquot and/or the second sample aliquot comprises at least one nucleic acid molecule and wherein the method comprises determining a base composition of the nucleic acid molecule from the molecular mass of the nucleic acid molecule.

9. The method of claim 4, comprising correlating the base composition of the nucleic acid molecule with an identity or property of the nucleic acid molecule.

Species specific and universal DNA probes and amplification primers to rapidly detect and identify common bacterial pathogens and associated antibiotic resistance genes from clinical specimens for routine diagnosis in microbiology laboratories

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